Geographical differences in whooping cough in Catalonia, Spain, from 1990 to 2010

Pilar Muñoz,Núria Soldevila,Gloria Carmona,Inma Crespo,Angela Domínguez,Pere Godoy

doi:10.1186/1471-2458-14-268

Abstract

BackgroundWhooping cough is a communicable disease whose incidence has increased in recent years in some countries with vaccination. Since 1981, in Catalonia (Spain), cases must be reported to the Public Health Department. In 1997, surveillance changed from aggregated counts to individual report and the surveillance system was improved after 2002. Catalan public health is universal with equal coverage geographically. The aim of this study was to determine whether there are differences in whooping cough incidence in rural and urban counties.MethodsCases in 1990–2010 were classified as rural or urban. Incidences and risk ratios (RR) between urban and rural counties and 95% CI were calculated. Associations between rural and urban counties and structural changes during the study period were analysed.ResultsTwelve years of the whole study period showed differences in incidence between rural and urban counties. The incidence was higher in urban counties in seven years and rural counties in five years. There was a positive association of whooping cough incidence in rural and urban counties in four-week periods. Structural changes were detected in the following four-week periods: 4th in 1993, 7th in 1996 and 3rd 2005 in rural counties and 5th 1993, 9th in 1996 and 8th in 2007 in urban counties.ConclusionsDifferences in whooping cough between rural and urban counties were found. In most years, the incidence was higher in urban than in rural counties. Rural and urban counties show similar cyclic behaviour when four-week periods were considered.

Highlights

Whooping cough is a communicable disease whose incidence has increased in recent years in some countries with vaccination
Whooping cough is a respiratory tract disease caused by Bordetella pertussis, a gram-negative bacterium, and was not preventable until the introduction of the whole-cell vaccine (DTwP)
Rural and urban incidences by year Between 1990 and 2010, 7540 cases of whooping cough were reported in Catalonia distributed in 27 rural counties and 14 urban counties (Figure 1)

Summary

Introduction

Whooping cough is a communicable disease whose incidence has increased in recent years in some countries with vaccination. Since 1981, in Catalonia (Spain), cases must be reported to the Public Health Department. Whooping cough is a respiratory tract disease caused by Bordetella pertussis, a gram-negative bacterium, and was not preventable until the introduction of the whole-cell vaccine (DTwP). From 1998 onwards, In Catalonia, cases of whooping cough must be reported to the Department of Health since 1981. From 1997 onwards, whooping cough reporting was individualized and made mandatory, and physicians had to make a specific report on each case [16]. In January 2003 [17], changes were introduced to increase case detection, facilitating diagnosis by PCR techniques and incrementing surveillance efforts by physicians to identify and report whooping cough [13]

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